May 2024 – Continued Warm and Dry Across Delaware

May Temperatures

Preliminary data indicates that the statewide average temperature in May was 65.2^°F, which is 1.6^°F above the 1991-2020 mean value of 63.6^°F (Figure 1).  May’s temperature was the 18^th warmest since records began in 1895.   May was also the 6^th month in a row in which temperatures have been above normal in Delaware.

May Precipitation

Delaware’s statewide precipitation for May 2024 averaged 2.46 inches, 1.12 inches below the 1991-2020 mean of 3.58 inches (Figure 2).  May’s precipitation was in the bottom one-third of values over the last 130 years.

Statewide Spatial Anomalies

Data from the Delaware Environmental Observing System (DEOS) show that temperature departures were positive across the entire state (Figure 3) with most locations seeing positive anomalies of between 1^°F  and 3^°F during the month.  Precipitation anomalies were varied across the state, with negative anomalies covering the entire State except for northwestern Sussex and southwestern Kent Counties (Figure 4).

National Anomalies

Temperatures were above normal across nearly the entire country with positive anomalies of 5^° to 7^°F found in the Great Lakes Region, as well as southern Texas and Florida (Figure 5). Only the Northwest portion of the country saw near or below normal temperatures.  Precipitation departures were varied across the country (Figure 6), as small-scale convective precipitation (thunderstorms) led to more localized precipitation anomalies.  The 500 hPa height pattern for May showed a jet stream trough across the Northwest U.S. (Figure 7) contributing to the lower temperatures in that region.

Global Anomalies

May 2024 ranked as the warmest May on record for the globe since 1850.  Global temperatures were 1.18^°C (2.12^°F) above the 1901-2000 mean of 58.6^°F.  Particular warmth was found across much of the Arctic and in portions of eastern North America, and much of Africa (Figure 8).

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